Astronomy & Space

Don’t miss Mercury’s greatest night present of the yr at nightfall from 20 February – Astronomy Now

February 19, 2019 • By
Innermost planet Mercury’s greatest night exhibiting of the yr for northern observers happens throughout the fortnight beginning 20 February, as simulated on this looping animation. UK skywatchers ought to discover a location that gives an unobstructed view of the horizon from west-southwest by means of west on the finish of civil twilight, which is about 40 minutes after sundown for the guts of the British Isles. Mercury is brightest (magnitude -1.0) in the beginning of the interval, and greatest considered from 25 February by means of 2 March when it’s 10° excessive on the finish of civil twilight. Warning: solely search for Mercury after sundown. AN graphic by Ade Ashford.

Each eager stargazer feels a quickening of the heart beat at seeing a transparent sky at nightfall. This sense intensifies when one is in with an opportunity of getting a naked-eye glimpse of Mercury, the photo voltaic system’s innermost planet. It’s rightly considered considerably elusive, however Mercury’s not notably troublesome to trace down if you happen to’re ready to do some homework to search out out when and the place to search for it. The innermost planet attains an elongation of 18.1 levels east of the Solar at 1:25am GMT on 27 February.

This yr’s best night apparition of Mercury for observers within the British Isles lasts a couple of fortnight beginning 20 February. First, it is advisable to discover a location that gives you an unobstructed view of the horizon from west-southwest by means of west on the finish of civil twilight, which is about 40 minutes after sundown for the guts of the British Isles. For any given day yow will discover out the time when civil twilight ends for the place you reside from our interactive on-line Almanac.

Mercury is brightest (magnitude -1.0) in the beginning of this two-week-long observing window round 20 February, and greatest positioned from 25 February by means of 2 March when it’s 10° excessive on the finish of civil twilight as seen from the guts of the British Isles. And I make no apologies for repeating the same old warning to guard your eyesight: by no means search for Mercury with binoculars or telescopes till after sundown.

Why it is a good time to search for Mercury
As winter segues into spring, many informal skywatchers at temperate latitudes such because the UK specific shock at how quickly the waxing younger crescent Moon quickly ascends within the western sky on successive nights, in stark distinction to nightfall in autumn when the Moon seems to hug the southwestern horizon. The illustration under explains why that is so.

How the season makes an enormous distinction to the visibility of a younger Moon or Mercury at sundown. The diagram represents the lunar crescent and innermost planet at its best easterly elongation from the Solar. As seen from temperate latitudes just like the UK throughout the spring, extra of the Moon and Mercury’s elongation from the Solar interprets into peak above the horizon as a result of the angle of the ecliptic is steepest to the western horizon, therefore the Moon or Mercury is seen for longer. The converse is true within the autumn when the ecliptic angle is shallow to the western horizon. Removed from this idealised state of affairs, the Moon and planets also can seem north or south of the ecliptic, additional affecting their visibility. AN graphic by Ade Ashford.